Kris5
Help :/ find all the roots by factoring or using the quadratic formula.. f(x)=x^4+5x^2+4
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To find the roots, we set f(x) = 0.
\(x^4 + 5x^2 4 = 0\)
Now, at first glance, this does not appear to be a quadratic equation. However, what happens if we made a substitution like u = x^2 ?
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oops, that should say
\(x^4 + 5x^2 + 4 = 0\)
Kris5
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ok
Kris5
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I'm stuck here...l
Kris5
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(4x^2) (4x^2-1)
phi
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with u= x^2
u^2 +5u +4 =0
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^ Yep. In this form, it becomes a quadratic equation!
So, now we are able to either factor or use quadratic formula with this equation.